Wanted: insulation payback QUICKLY!!
I just got to look at a house built in the 1880’s. The house has no insulation in the walls (but the window counterweights have been removed and those cavities are insulated, but the windows are stil teh original). Two story. About 160 feet of exterior wall. It has vinyl siding.
They run a humidifier in the winter.
There is some insulation in the attic. There is a floor in the attic and someone drilled holes and blew cells into the joist cavities. Joists are 2×6. Attic floor area (and floor area on each level) is about 1250n sq. ft.
Judging from what is visible at various places where there is a hole in the floor (mostly to accomodate wiring), the cells are not exactly dense packed, in some places there are only a couple of inches.
It does seem clear that no effort has been made to seal the attic floor. Downstairs walls are balloon framed and one spot where the hole in the attic floor is above a wall, the top of the wall is completely open.
Homeowners are an elderly couple. They are concerned about the continuing rise in the gas bill. They claim it has gone from $1,100 dollars a year to $2,300 a year (I’m not sure how long ago it was $1,100).
The homeowners have specifically said that they do not want to spend what they will not recoup in lower utility bills.
I figure that dense packing cells into the 160 feet of twenty foot high side walls at about $2,600 (any thoughts on that price?).
I figure the cutting paths out of the attic floor above the 2nd floor walls and holes above the fixtures and sealing the same to be $1,200.
I’m thinking that they may or may not see the payback on the sidewall insulation, but that sealing the attic floor might just do the trick.
What do you think? What will save the customer money in a short time frame (five, ten years).
Thanks.
Rich Beckman
Another day, another tool.
Replies
My brother is in the process of conveting Grandma's old house (built 1913) to his business office. House was similarily open, remember the gas bill was $30 a month in 1968 when a therm was only 4 cents or so (coal furnace conversion, 25% efficiency was probably good. In Springfield, IL, so similar climate to Indiana.
Attic insulation and sealing is first payoff as you have surmised. Newspaper sealing on storm windows does wonders also, always did that in the 50's in IL.
We calculated that the payback (NOT including DIY labor) for the attic insulation (900 sq feet) was less than 5 months.
All the plaster was disintegrating so stripping all the walls and insulated, not feasible in your case, but the attic sure is.
Once the insulation was in we took the trade one step further, as seen in the attachment. Did the Goodman heat pump installation with flex ducts myself last fall, total cost after $480 power company (municipal) rebate was only $1100, lowest local pro bid for install with sheet metal ducts and Trane HP was $6000, so payback would be 5X longer, likely not cost effective in your case, esp as (LG&E??) is likely higher kW-hr rate than Spfld.
"My brother is in the process of conveting Grandma's old house (built 1913) to his business office."
What's he gonna do with all the bikes ???
(-:
My mind not only wanders, it sometime leaves completely.
Ron: Like you said about the propane tanks, put them on the street with a price on them and they will dis-appear about 2 AM. Did get rid of a few hundred of the bikes and a few stolen in a break in (not much insulation value in them-why didn't they just ask??), only about 50 still in the basement.
Going to be in Springfield June 16-19th, think my brother has a few score of bales and a blower lined up for my "vacation" 'pleasure' -- he says at least he has already gotten all the plaster and lath disposed of and drywall installed on the 2nd floor ceiling where the plaster had fallen off.
If you make it to town, let me know. Carl and I might venture up that way to visit.
A man's got to do what a man's got to do. A woman must do what he can't. [Rhonda Hansome]
Are we talking bicycles?
(old ten speed fan.....went in a bike shop after 20 years out of the sport & was amazed/depressed by how high tech/pricey it has become)
Junkhound,Thanks for the reply."Newspaper sealing on storm windows does wonders also, always did that in the 50's in IL."What is "newspaper sealing"?I don't think the idea of a new furnace/heat pump/whatever even occurred to me. When I go back I will certainly ask about how old the current furnace is. It does seem that the duct in the attic didn't look all that old.Rich BeckmanAnother day, another tool.
"newspaper sealing"
There is always a gap between the sash and frame on those old windows, and storm sash often had a faily loose fit. The weekend after Haloween was the time to take down the screens and put up the storm sash. (My parents left up the storm windows after they got AC sometime in the 80's)
OK, so when you put up the storm sash, it is made into a slight "press fit" by the judicious application of folded and semi-crumpled layers of newspapers - I'll bet your homeowners know about this already. Pretty much a poor mans weatherstripping on storm sash. At the same time, the double hung window gaps that were not well "painted shut", were also stuffed with newspapers to eliminate drafts. It sounds like if the sash weight have been removed and that cavity insulated the window may already be sealed in place???
Also, the attic windows were left open in the summer, and in the Haloween makeover masking or duct tape was used on the inside gap between window and frame to seal the gaps - actually just did this last fall again on Mom's house. .
Here is a link for a decent heat loss program. http://www.weil-mclain.com/netdocs/programs.htm Changing the infiltration rate has amazing results.Build the house as one big box to simplify things.
My house wasn't as bad as you describe... and I haven't finished yet.I went from 35% efficient to 63% efficient and have chopped my gas bill from about $2000 per year to $600 per year. Add about $250 per year to the electric bill for hot water and there you have.Major items. Weatherstripping and air sealing. Excellent article in the energy efficiency section of this site.In the category of air sealing one thing we did was spray 3" of polyurethane to seal up the rim joist to the foundation wall. I have read studies indicating you could be losing around 15% of your heat just through that.New high efficiency furnace.The attic floor was insulated pretty much as you described. I did insulate the attic door and weather strip it as well.The attic will happen this summer (properly now).If my house wasn't a 100 years old... there would go a really fine hobby.
"In the category of air sealing one thing we did was spray 3" of polyurethane to seal up the rim joist to the foundation wall."
Rich, DgH has good advice. I have heard that 25% of house air infiltration is rim joist/sill plate/foundation wall. Note that BuildingScience.com articles on basement finishing emphasive methods of sealing this area by tying the top of the basement wall into the sill plate and sealing rim joist bays.
A labour-intensive (but probably still cheaper than full spray foam application) for sealing rim joist bays is to cut XPS foam insulation 1/2" undersize and gluing it to the rim joist, then foaming the 1/2" open perimeter with standard expanding insulation foam. If this can then be tied into a basement wall insulation that extends 4 feet below grade, even better.
Here's a pictorial of rehabbing an old house:
http://www.buildingscience.com/about/our_house.pdf
And a detail drawing of insulating walls (new construction, but still useful - note the emphasis on sealing):
http://www.buildingscience.com/housesthatwork/cold/denver.pdf
Regards,
Tim Ruttan
The customer is going for the sealing of the attic floor for $1,200.They will give that a winter and see how they feel about other work.I start tomorrow.Rich BeckmanAnother day, another tool.
In general, sealing leaks is cheaper and more cost-effective than insulating, up to a point that is frequently never reached. It's just a PITA, so folks don't like to do it.
However, one way to seal leaks is to blow in dense-packed cellulose. Also, if you do seal the joist cavity openings into the attic, you need to do it in a way that's reasonably reversible, so that cells can be blown in in the future.
I'd want to analyze the entire structure, however, from the ground up. If there's a crawlspace then the bottom floor may be a major source of leakage, eg. Also, having a cold floor makes folks more uncomfortable, and so they tend to turn the heat up higher.
In terms of payback, though, it sounds like it wouldn't be difficult to reduce heating costs by 20-30%. Over five years that's $2300-3450, if I'm doing my math right. You have a fairly reasonable working budget.
Dan,There is a partial basement, the rest crawl. I haven't been down there.They quickly established that they wanted a quick payback, so I assumed that would be found in the attic.Good point about the floor though.Thanks.Rich BeckmanAnother day, another tool.
'They do not want to spend what they wont recoupe in savings'
1. How long are they planning on staying there?
2. There is their own comfort to consider.
3. There is resale value in insulating a home.
4. Many utilities offer rebates for insulating older homes ($1500 in MA).
"1. How long are they planning on staying there?"They were not definite on this, but I got the impression they were planning to die there and that they weren't looking past ten years."2. There is their own comfort to consider."They claim they are already very comfortable."3. There is resale value in insulating a home."I don't think they care about that since they plan on being dead, but it is a good point."4. Many utilities offer rebates for insulating older homes ($1500 in MA)."Indiana offers a tax deduction of $1,000 (at least they have for several years now). Of course, since the tax rate is 3.4%, that is only worth $34.00. I'll have to check into the gas company.Thanks.Rich BeckmanAnother day, another tool.
No doubt that sealing the attic plane has the best cost/benefit analysis in nearly every case. Don't forget the gap around any masonry chimneys. Seal with metal and RTV silicone.
Exfiltration is higher priority than infiltration (sill plates and such). The cold air will not come in at the bottom if there is no warm air leaving at the top to displace. Folks are quick to replace windows, but the cost/benefit ratio for that is poor.
After sealing all of the obvious holes, a blower door test may be a worthwhile investment. That way you can see where you are, and find the next weakest link.